1. Field of the Invention
The present invention generally relates an induction generator or motor which is capable of direct connection to the electrical grid or other variable load or power source. One example of such a generator is a wind turbine.
2. Introduction
The present application relates to induction generators and motors. One example of these types of devices is the wind turbine. Small wind turbines are increasingly being used for residential generation of power. A wind turbine is a machine that converts the kinetic energy of the wind into mechanical energy. The mechanical energy is then typically converted into electricity. Wind turbines may rotate on a horizontal or vertical axis. Most small wind turbines employ permanent magnets generators to create “wild-AC” which is a variable voltage having a variable frequency power. This power must first be converted to DC and then back AC via an inverter. The inverter then produces standard 60 cycle AC synchronized to the power grid, at 120V or other common voltage. This voltage is required to be of a given quality and synchronized with the utility grid power in order for the power to be used seamlessly in the home. Induction generators offer a cost-effective alternative to inverters for creating grid-compatible power. What is needed in the art are improvements to make induction generators more efficient in grid-connected, in particularly at low power levels.